1. Field of the Invention
Surgery: surgical instruments; coaptators; hook-crack devices; serrefines; clamps; expanding arms.
2. Description of the Prior Art
The heart is the muscular organ that pumps the blood. The heart is divided into four chambers - two ventricles referred to as the left and right ventricle, and two auricles referred to as the left and right auricle. The blood flow through these four chambers is controlled by four valves. Two of the valves, the mitral valve and the aortic valve can become diseased through injury or infection, or either can be genetically imperfect. These two valves can be surgically removed and replaced with an artificial heart valve. Techniques nowadays include surgical machines or life support systems that are available in open heart surgery to allow the blood flow from the patient to be diverted to a heart-lung machine. The heart can be stopped while the surgeon performs surgery and repair upon the patient's heart.
The heart is contained within the thoracic, or chest cavity, and it is enclosed within a pericardium sac, which contains a fluid mixture that tends to lubricate the heart while it beats. The heart and pericardium are naturally positioned within the thoracic cavity underneath the body of the sternum, commonly referred to as the breast bone. The breast bone interconnects ribs 1 through 7 of the patient. In order for the surgeon to operate on the heart, he or she obviously has to have access to it. It is now standard procedure to access the heart by making a surgical incision beginning at the throat area and cutting medially the entire length of the sternum by incision and also by cutting through the sternum with a small electric saw. The gap created by the cut and separated sternum allows the surgeon to insert a sternum spreader (occasionally termed a retractor instrument) in between and the edges of the cut sternum. The sternum spreader (retractor) tool is cranked open until the two spreader arms, which abut the sternum edges, force the sternum and rib cage to separate and expand open giving access to the pericardium and enclosed heart within the thoracic cavity.
Artificial heart valves have a circular ring shape arc of the the following designs: a closed ball-and-cage; a tilting disk, and a pig valve in the ring.